Adjustable screen frame for rear projection screen or the like

ABSTRACT

An adjustable screen frame assembly composed essentially of tubular members which are rectangular in cross section, the tubular members defining the corners legs, and side parts of the screen frame, the frame assembly including T-shaped sections which are telescopically received in the tubular parts and wedged into multiple point clamping engagement therewith by means of adjustment bolts, the frame forming parts being provided with means for readily attaching a screen or the like thereto.

United States Patent Inventor John F. Dreyer Cincinnati, Ohio 885,696

Dec. 17, 1969 June 8, 1971 Polncoat Incorporated Cincinnati, Ohio Appl. No. Filed Patented Assignee ADJUSTABLE SCREEN FRAME FOR REAR PROJECTION SCREEN OR THE LIKE 9 Claim, 9 Drawing Figs.

U.S. Cl 160/351, 160/377, 160/381 Int. Cl A47g 5/00 Field 01 Search 160/135,

[56] References Cited UNITED STATES PATENTS 839,501 12/1906 Munro 160/351 2,357,819 9/1944 Greer 160/377 X 2,571,382 10/1951 Raven 160/351 X 3,494,405 2/1970 Sandahl et a1. 160/378 X Primary Examiner-Peter M. Caun Attorney-Melville, Strasser, Foster and Hofi'man ABSTRACT: An adjustable screen frame assembly composed essentially of tubular members which are rectangular in cross section, the tubular members defining the corners legs, and side parts of the screen frame, the frame assembly including T- shaped sections which are telescopically received in the tubular parts and wedged into multiple point clamping engagement therewith by means of adjustment bolts, the frame forming parts being provided with means for readily attaching a screen or the like thereto.

PATENTED JUN 8 l97| SHEET 1 BF 3 INVENTORf John F. Dreyer A T T O R N E YS PATENTEUJUN 81971 3583466 SHEET 2 OF 3 INVENTOR,

John F. Dreyer BY -.%1Iddr, all/W11)! ATTORN EYS ADJUSTABLE SCREEN FRAME FOR REAR PROJECTION SCREEN OR THE LIKE BACKGROUND OF THE INVENTION The present invention relates to a screen frame particularly suited for mounting rear projection screens of various sizes. In many instances, rear projection screens are custom made to the particular dimensions desired the user, and vary quite widely in size. One of the problems faced by the screen manufacturer is the economical production of screen frames which may be readily adapted to screens of different sizes. If the frames are custom build for each different size screen, they usually require special parts and fittings which must be die cast and finished, or machined, with different sizes and shapes of parts being employed for different size frames. Similarily, numerous sizes of frame material must be maintained in stock in order to fill the requirements for any particular frame size which may be required.

While numerous forms of adjustable screen frames have hitherto been proposed, including the use of telescoping frame members and the like, the use of conventional telescoping parts can add materially to the cost of a given size frame, particularly where the desired dimensions of the frame are only slightly larger than the fully telescoped length of the frame members being used.

In contrast to the foregoing, the instant invention contemplates a screen frame construction which affords a wide range of adjustability so that a frame of any desired size may be readily assembled utilizing a minimum of parts and with a minimum of surplus material. Thus, the screen manufacturer may readily fabricate a screen of any desired size utilizing stock parts, without the necessity for custom fitting or other special work. At the sarre time, the frame assembly is such that it may be readily disassembled for storage in a minimum amount of space.

While particularly suited for rear projection screens, the instant invention also may be employed with conventional front projection screens and for other uses wherein it is desired to support a screenlike member.

RESUME OF THE INVENTION The basic components of the screen frame comprise readily available tubular stock which is either square or rectangular in cross section, and T-shaped sections of a size to be telescopically received within the tubular stock. In a preferred embodiment of the invention only one size (cross-sectional dimen' sions) of T-shaped section is required, and only two sizes (cross-sectional dimensions) of tubular stock are required. In another embodiment, only one size of tubular stock is required.

The frame assembly has a pair of legs each formed from tubular stock and comprising a horizontally disposed floor-contacting member and a vertically disposed post projecting upwardly from the center of the horizontal member. The legs can be readily fabricated by simply welding together two pieces of the tubular stock in the desired relationship. The frame has four identical comer parts each of which is fabricated from a single length of tubular stock. To this end, each corner part is formed by medially severing a length of tubular stock along three adjoining side edges and then bending it along the remaining side edge until the opposite halves lie at right angles to each other. In the preferred embodiment, both the leg and comer parts will be formed from the larger of the two sizes of tubing, with the sides of the frame formed from the smaller size tubing which may be provided in any desired unit lengths.

In accordance with the invention, the legs are connected to the lowermost corner parts by means of T-shaped sections which are telescopically received in the vertical posts of the legs, the posts and corner parts each being provided with an adjustment bolt, such as a wing bolt, which engages the web of the T-shaped section and forces it into clamping engagement with the inner surfaces of the tubular members. Actually, a wedging action takes place with the T-shaped member being LII turned within the surrounding tubular member so that there is effectively a three-point clamping engagement between the T- shaped section and adjoining walls of the tube.

In the preferred embodiment similar T'shaped sections are utilized to interconnect the tubular members defining the sides of the frame, the T-shaped sections being telescopically received in adjoining frame members and adjustably clamped in place by means of wing bolts or the like. In the other embodiment, the T-shaped sections themselves constitute the frame members, with tubular sleeves provided to interconnect the T-shaped sections.

The screen itself may be readily attached to the assembled frame by means of hooks spaced apart along the edges of the screen, the hooks being engageable either in spaced apart openings in the outermost surfaces of the tubular frame and corner parts, or the tubular frame parts may be provided with projecting flanges adapted to be engaged by the hooks. Where the frame parts are formed from T-shaped sections, a base edge of the section defines the flange.

The versatility of the invention lies in the fact that by providing frame parts in standard lengths, such as three feet, four feet, and five feet, and employing corner parts each having an effective length or depth between four feet and seventeen feet. Of course, by varying the dimensions, other size ranges may be readily developed.

DESCRIPTION OF THE DRAWINGS FIG. I is an exploded rear perspective view of a screen frame in accordance with the invention.

FIG. 2 is an enlarged fragmentary perspective view illustrating the details of the leg and corner construction.

FIG. 3 is an enlarged fragmentary perspective view illustrating the attachment ofa screen to the frame.

FIG. 4 is an enlarged vertical sectional view taken along the line 4-4 of FIG. 3.

FIG. 5 is an enlarged vertical sectional view similar to FIG. 4 illustrating a modified construction for the tubular frame parts.

FIG. 6 is an enlarged sectional view taken along the line 6-6 of FIG. 2.

FIG. 7 is an exploded form perspective view of a modified form of screen frames.

FIG. 8 is an enlarged vertical sectional view taken along the line 8-8 of FIG. 8.

FIG. 9 is an enlarged vertical sectional view taken along the line 9-9 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment illustrated in FIG. 1, the frame is composed of a pair of leg parts I and 2 each having a horizontally disposed base 3 formed from tubular stock and an upstanding, usually medially disposed, tubular post 4 which is preferably welded to the base 3. As seen in FIG. 2, the ends of the tubular base 3. As seen in FIG. 2, the ends of the tubular base 3 may be conveniently closed by plastic inserts 5.

T-shaped sections 6 and 7 are adapted to be received in the posts 4 of leg parts 1 and 2, T-shaped sections each having a base 8 and a web 9, the sections being oriented so that their bases will be juxtaposed to the innermost side edges of the posts 4. To this end, the dimensions of the T-shaped sections will be such that they will be freely receivable within the tubular posts 4. In an exemplary embodiment wherein the tubular posts 4 are formed from 18 gauge stock and the T-shaped sections have a body thickness of one-eighth inch, the base 9 will have a width of 1 inch, whereas the outside dimension of the sides of the tubular member will be 1% inches. The sections 6 and 7 are also adapted to be received in tubular corner parts 10 and 11 which, along with the corner parts 12 and 13, define the four corners of the screen-supporting parts of the frame assembly. Each of the corner parts is identical and has a vertically disposed socket l4 and a horizontally disposed socket 15, the sockets preferably being formed by medially severing a length of tubing along three adjoining side edges and then bending the ends at right angles to each other along the remaining side of the tubing. In order to strengthen the corner joint so formed, it is preferred to apply a fillet 16 (FIG. 2) of welding material to strengthen and reinforce the corner joint. The corner posts may be conveniently formed from 18 gauge tubular stock having an outside diameter of 1% inches.

The T-shaped sections 6 and 7 are adapted to be clamped to the vertical posts 4 of the leg parts and to the vertical sockets 14 of the lower corner parts by means ofthe thumb bolts 17 and 18, respectively, which are adapted to bear against the webs 9 of the T-shaped sections. Thus, as illustrated in FIG. 6, the thumb bolt 17 passes through the wall of the socket 141 where it engages the adjacent side of web 9 of the T-shaped section 7. While the thumb bolts could be received in threaded openings in the tubular members, the threading of the openings can be eliminated by the use of nuts, such as the nut 180, which permits the thumb bolt to be tightened against the web of the T-shaped section. The thumb bolt affords a tight, wedging engagement of the parts at three spaced apart points, indicated at A, B and C, which effectively prevents slippage of the parts relative to each other once the thumb bolt has been tightened.

The sides of the frame extending between the comer parts are defined by sets of tubular members 19 and 20. In the embodiment illustrated, all of the members 19 will be of equal length, and all of the members 20 will be of equal length, although preferably the members 19 will be of a different length than the members 20. The members 19 and 20 will also be formed from tubular stock, but the stock will be slightly smaller in cross-sectional dimensions than the stock from which the comer parts are fonned so that the ends of the members 19 and 20 may be received in the sockets l4 and of the comer parts. Tubular stock of 18 gauge having an outside diameter of 1% inches may be conveniently used. The comer parts are provided with stops, such as the stops 21 and 22 seen in FIG. 2, which comprise inwardly bent flaps formed in the walls of the socket, the flaps being adapted to be contacted by the ends of the frame members 19 and 20, thereby establishing their fully assembled position within the sockets.

The frame members 19 and do not telescope relative to each other; rather, they are joined together by T-shaped sections 23 which are identical to the sections 6 and 7, although preferably of shorter length the T-shaped sections 23. The sections 23 thus serve to interconnect the frame members 19 and 20 and also serve as a means for varying the length of the side of the frame within the limits of the length of the sections 23, which may be 8 inches.

The manner in which the screen is attached to the framemembers can be best seen in FIGS. 3 and 4, wherein the screen 26 is provided with a plurality of spaced apart hooks 27 adapted to engage in openings 29 formed at spaced apart intervals along the outermost sides of the corner parts, as well as along the frame members 19 and 20. Preferably, the distance between the openings 2% will be uniform. In a preferred embodiment, the openings will be on 6 inches centers, except adjacent the juncture of the sockets M and 15 of the corner posts, where the endmost openings may be spaced a lesser distance, thereby providing support for the screen immediately adjacent its comers. In addition, the number of openings in each of the frame members 19 and 20 should be a whole number divisible into the length of the frame member, i.e., if the length of the frame member is 3 inches, the openings should be spaced apart by a distance of 3 inches, 4 inches, or 6 inches, with the latter being preferred for practical purposes. It is also preferred that a half-opening be provided at each end of the frame member so that, when two adjoining frame members are juxtaposed in end-to-end relation, the two halfopenings will mate to form a full opening at the juncture of the two frame members. Again, with reference to a frame member having a length of 3 inches, with the opening spaced apart a distance of 6 inches, there would be a half-opening at each end of the member with five intervening full openings. In

order to insure continuity of spacing of the openings as between the frame members 18 and 19 and the sockets of the corner posts, the inturned stops 21 and 22 will be aligned with the center lines of the outermost hook receiving openings in the sockets 14 and 15, thereby insuring uniformity of spacing between the said openings in the socket and the corresponding openings in the frame members.

The construction just described provides a frame assembly which may be readily tailored to mount a screen of literally any desired dimensions, the screen size being altered by the choice oflengths for the frame members 19 and 20. For example, by providing the frame members 19 and 20 in lengths of 3 inches, 4 inches, and 5 inches with the effective length of the sockets 141 and 15 being 6 inches, i.e., the distance between the absolute corner edge of the frame and the stops 21 and 22 being 6 inches, any screen size can be accommodated between a minimum of 4 inches on a side and a maximum of 11% inches on a side, where the intervening T-shaped sections 23 have an effective useful length of 6 inches. Obviously, however, the dimensions of the parts may be changed to provide literally any desired range of screen sizes. In addition, the screen frame may be raised and lowered relative to the leg parts 1 and 2, depending upon the length of the T-shaped sections 6 and 7, which, in a preferred embodiment, are 4 inches in length and hence capable of extending upwardly through the sockets l4 and into the lowermost vertical frame members 19. In the event it is desired to position the screen with the lower horizontally disposed frame members 19 and 20 seated on the supporting floor surface or the like, the T-shaped sections 6 and 7 may be inserted in the horizontally disposed sockets 15 of corner parts 10 and 11, with the leg parts 1 and 2 projecting outwardly from the frame in a horizontally disposed condition.

Modifications may be made in the invention without departing from its spirit and purpose. For example, while in the embodiment illustrated in FIG. 1, pairs of frame members 19 and 20 have been illustrated, it will be evident that each side of the frame could be composed of one, two, three, or even more tubular frame members of the same or differing lengths, depending upon overall size requirements. In this connection, it will be understood that where two or more tubular frame members are to be connected together end-to-end they will be joined by T-shaped sections corresponding to the sections 23. It is also within the spirit of the invention to form the tubular frame members, such as the members 18 and 19, with projecting flanges adapted to be engaged by the hooks 27 of the screen. Thus, as illustrated in FIG. 5, the tubular member 29 may be provided with projecting flanges 30 engageable by the hook 27 in the manner illustrated. Such flanged tubular members may be received directly in the sockets l4 and 15 of the corner parts, in which event the corner parts will have openings 28 as before, although the corner parts also may be of flanged construction with the corner part engaging hooks either offset or elongated to engage about the flanges. Alternatively, the dimensions of the flanged tubular members 29 can be related to the dimensions of the sockets of the corner parts so that the projecting flanges 30 and 31 may be cut off at one end of the tubular member, thereby permitting the end portion with the flanges removed to be received in the socket.

A modified version of the screen frame is illustrated in FIG. 7, wherein like parts have been given like reference numerals. Thus, in this embodiment, the frame includes leg parts 1 and 2, formed as in the embodiment of FIG. 1, except in this instance the thumb bolts l7a are arranged to extend through the inner sides of the posts 4. Similarly, the frame is provided with comer parts 10, 11, 12 and 13, each such corner part being provided with pairs of thumb bolts 31, 32, extending through the sockets 14 and 15, respectively, of the corner parts. The frame also includes vertically disposed T-shaped sections 611 and 70 adapted to be received in the posts 4 of the leg parts 1 and 2, but in this instance the T-shaped sections are oriented so that their bases 8 will be juxtaposed to the forwardly facing sides of the corner posts 4, with the thumb bolts 17a engaging the webs 9 of the sections. It is also preferred that the sections 60 and 7a project upwardly through the corner parts to define the opposing sides 33 and 34 of the frame, the uppermost ends of the sections being received in the sockets 14 of the corner parts 12 and 13 where they are fixedly secured in place by means of the thumb bolts 31.

In this instance, the upper and lower sides of the frame are defined by pairs of T-shaped sections 35 and 36 positioned with their bases 8 facing forwardly. With such arrangement, when the ends of the frame-forming T-shaped sections are inserted in the sockets 15 of the corner posts, they will be locked in place by the thumb bolts 32. The frame-forming sections 35 and 36 are joined together by means of tubular sleeves 37 provided with sets of thumb bolts 38, 39 adapted to engage the ends of the sections 35 and 36, respectively. It will be evident that the sections 35 and 36 may be made of any desired unit lengths, with two or more such lengths joined together by means of sleeve members 37. Similarly, it is within the spirit of the invention to provide additional T-shaped sections joined to the upper ends of the extensions 33 and 34 of the vertically disposed sections 60 and 7a,thereby effectively increasing the length of the opposite sides of the frame. As will be evident from FIG. 8, the hooks 27 of the screen 26 may be engaged about the uppermost edge of leg 8a forming a part of the base 8 of the T-shaped section. Similarly, as seen in H0. 9, the tubular sleeves 37 may be provided with openings 28a, similar to the openings 28 illustrated in the embodiment of FlG. 4, in which the hooks 27 may be engaged. F l0. 9 also serves to illustrate the manner in which the thumb bolt 38 engages the web 9 of the frame-forming section 35.

In the embodiment just described, all of the tubular parts may be of the same cross-sectional dimensions, and consequently, only one size tubing is required. The T-shaped sections will be of a size to be telescopically received within the tubular members, but it will be evident that the lengths of the sections may be varied, as in the case of the preferred embodiment, to thereby provide a screen frame of the desired dimensions. It will also be evident that the hooks 27 of the screen may be readily accommodated to engage either tubular or T- shaped frame-forming members.

The embodiments of the invention in which I claim as an exclusive property or privilege are defined as follows:

1. In an adjustable screen frame assembly;

a pair of leg parts each having a tubular post which is rectangular in cross section;

a set of four corner parts each composed of an interconnected pair of tubular sockets extending at right angles to each other, said sockets being rectangular in cross section;

a set of frame members of a size to be telescopically received in the sockets of said comer parts,said corner parts and said frame members, when assembled, defining parts of a rectangular screen supporting frame;

a pair of T-shaped sections of a size to be telescopically received in the tubular posts of said leg pans and in the tubular sockets of said corner parts; and

clamping means operatively connected to said posts for securing the ends of said T-shaped sections therein, and additional clamping means operatively connected to said sockets for engaging the portions of the T-shaped sections extending therethrough, whereby the rectangular screen frame so formed may be raised and lowered relative to said leg parts.

2. The adjustable screen frame assembly claimed in claim 1 wherein said frame members and said corner posts include means for detachably connecting a screen thereto.

3. The adjustable screen frame assembly claimed in claim 2 in combination with a screen having spaced apart hooks along its edges engageable with said screen mounting means.

4. The adjustable screen frame assembly claimed in claim 3 wherein said screen mounting means comprises spaced apart openings positioned to be engaged by said hooks.

5. The adjustable screen frame assembly claimed in claim 3 wherein said screen mounting means comprises flange members engageable by said hooks.

6. The adjustable screen frame assembly claimed in claim 1 wherein said frame members are tubular in cross section.

7. The adjustable screen frame assembly claimed in claim 6 wherein at least an opposing pair of the sides of said screen frame are each composed of a plurality of tubular frame members, and wherein said last named tubular frame members, and wherein said last named tubular frame members are connected together by T-shaped sections telescopically received in the adjoining ends of the said tubular frame members, including clamping means for fixedly securing said T-shaped section to said tubular members.

8. The adjustable screen frame assembly claimed in claim 1 wherein said frame members comprise T-shaped sections.

9. The adjustable screen frame assembly claimed in claim 1 wherein at least an opposing pair of the sides of said screen frame are each composed of a plurality of T-shaped sections, wherein said last named frame members are connected together by tubular sleeves in which the adjoining ends of the members are telescopically received, including clamping means for fixedly securing said tubular sleeves to said T- shaped sections. 

1. In an adjustable screen frame assembly; a pair of leg parts each having a tubular post which is rectangular in cross section; a set of four corner parts each composed of an interconnected pair of tubular sockets extending at right angles to each other, said sockets being rectangular in cross section; a set of frame members of a size to be telescopically received in the sockets of said corner parts, said corner parts and said frame members, when assembled, defining parts of a rectangular screen supporting frame; a pair of T-shaped sections of a size to be telescopically received in the tubular posts of said leg parts and in the tubular sockets of said corner parts; and clamping means operatively connected to said posts for securing the ends of said T-shaped sections therein, and additional clamping means operatively connected to said sockets for engaging the portions of the T-shaped sections extending therethrough, whereby the rectangular screen frame so formed may be raised and lowered relative to said leg parts.
 2. The adjustable screen frame assembly claimed in claim 1 wherein said frame members and said corner posts include means for detachably connecting a screen thereto.
 3. The adjustable screen frame assembly claimed in claim 2 in combination with a screen having spaced apart hooks along its edges engageable with said screen mounting means.
 4. The adjustable screen frame assembly claimed in claim 3 wherein said screen mounting means comprises spaced apart openings positioned to be engaged by said hooks.
 5. The adjustable screen frame assembly claimed in claim 3 wherein said screen mounting means comprises flange members engageable by said hooks.
 6. The adjustable screen frame assembly claimed in claim 1 wherein said frame members are tubular in cross section.
 7. The adjustable screen frame assembly claimed in claim 6 wherein at least an opposing pair of the sides of said screen frame are each composed of a plurality of tubular frame members, and wherein said last named tubular frame members, and wherein said last named tubular frame members are connected together by T-shaped sections telescopically received in the adjoining ends of the said tubular frame members, including clamping means for fixedly securing said T-shaped section to said tubular members.
 8. The adjustable screen frame assembly claimed in claim 1 wherein said frame members comprise T-shaped sections.
 9. The adjustable screen frame assembly claimed in claim 1 wherein at least an opposing pair of the sides of said screen frame are each composed of a plurality of T-shaped sections, wherein said last named frame members are connected together by tubular sleeves in which the adjoining ends of the members are telescopically received, including clamping means for fixedly securing said tubular sleeves to said T-shaped sections. 